How to fix cldflt.sys Windows 11 BSOD blue screen error

How to fix cldflt.sys Windows 11 BSOD blue screen error. Blue screen is a headache that pops up with system crashes, hangs and freezes. The error, with default settings, forces the PC to restart at the same time. In some cases, after rebooting, the Blue screen still appears and then you need to continue to start the repair task. Cldflt.sys is an error that can be seen along with various stop codes. This can be a system service exception, an unpaged zone page fault, an unhandled kmode exception, an unhandled system string exception, and a kernel data page. In all cases, the BSOD shows What failed: Cldflt.sys, which means that the system failed due to the error of this file.

Cldflt.sys BSOD mainly occurs due to third party programs installed on your computer. Furthermore, incompatible device driver versions are the root cause in some cases. Faulty Windows updates, corrupted system files, presence of malware are other major factors that can lead to this Blue Screen error. cldflt.sys refers to Cloud Miniature Filter Driver files used as drivers in Windows 11 and 10.

How to fix cldflt.sys Windows 11  BSOD blue screen error
How to fix cldflt.sys Windows 11 BSOD blue screen error

How to fix cldflt.sys Windows 11 BSOD blue screen error

Here is how to fix Cldflt.sys BSOD Blue Screen Error in Windows 11 or 10 –

Method-1: Modify the registry entry

To fix the Blue Screen issue related to the Cloud File Small Filter Driver, modifying the following registry works like a miracle –

  1. Press – Winkey + R .
  2. Type – regedit .
  3. press – Enter .
  4. When the Registry Editor appears, navigate to the following location:

Computer -> HKEY_LOCAL_MACHINE -> SYSTEM -> CurrentControlSet -> Services -> CldFlt -> Instances

  1. Right click on DefaultInstance and select – Modify .
  2. In the Value data field, enter CldFlt and click OK .
  3. Close Registry Editor and restart your PC.

Method 2: Uninstall third-party programs

You may experience problems after installing or updating Keypass or the KeypassOneDriveSync utility. Many users have shared their pain related to Cldflt.sys blue screen issue on GitHub and other tech forums. Some other users reported encountering this error when they installed another program. A better way to fix this problem is to uninstall Keypass or the utility depending on what is causing the error. However, you can take the opportunity to update the Keypass. And, always remember to install the latest software version.

  1. Press – Windows+R .
  2. Type – appwiz.cpl .
  3. Type – Enter .
  4. The Programs and Features window will appear, displaying a list of all installed software.
  5. Find the extension you want to uninstall and right-click on it.
  6. Option – Uninstall .
  7. Click Yes if a confirmation prompt appears.
  8. Reboot the system and see if Cldflt.sys Bsod persists.

Method-3: Install Windows Updates

When you get Something Failed: Cldflt.sys with any error checking Windows Updates can help you fix this problem. Previously Microsoft submitted a solution in KB4522355 exclusively in this respect. So let’s install the update without wasting any more time –

  1. Click Search located on the taskbar.
  2. Type – updates .
  3. Press – Enter .
  4. Once the Settings app is loaded, click Check for updates .
  5. The system will start looking for updates immediately. Please take a few minutes to download depending on the speed of your internet connection.
  6. Once the download is complete, you will be asked to choose a time to install the update. Select – Restart now .
  7. Then hopefully you won’t see the BSOD error.

Method-4: Update device drivers

Cldflt.sys BSOD error can also appear when any device driver is out of date. In fact, the old driver file creates conflicts with system components that eventually convert to a stop error. You know that driver software is needed to establish communication between the hardware and the Windows operating system. As it becomes obsolete, incompatibility issues start leading to conflicts between drivers and system files. When the system calls the file Cldflt.sys, it receives no return and the blue screen of the problem occurs. Therefore, update all drivers from Device Manager using the guidelines below –

  1. Press – Winkey+R .
  2. Type – devmgmt.msc .
  3. Type – Enter .
  4. After Device Manager loads, click on the categories one by one. Under each one you will find a list of drivers. You need to make sure that anyone doesn’t show a yellow exclamation point. This icon is an indication of an outdated driver.
  5. If an exclamation mark is showing then right click on it and select – Update driver .

  1. Click on – Search automatically for drivers .
  2. Repeat the same for all outdated drivers there.
  3. Restart the device and check if the blue screen is resolved.
  4. If you still see the blue screen then check the driver that is showing the exclamation mark.
  5. However, the mark appears then right click again and select – Update drivers .
  6. This time, click on – Browse my computer for drivers .
  7. On the next window, select – Let me pick from a list of available drivers on my computer .
  8. Click Next .
  9. Now finally restart the PC.

How to Uninstall, Disable, Restore, Update Device Drivers in Windows 10/8/7

Method-5: Run System File Checker aka SFC

Corrupted system files is a vast process that can cause a number of errors. As far as the Cldflt.sys BSOD question is concerned, that error is caused by a conflict between the corrupted .sys file and the Windows components. Since system files are the basis, the PC fails to boot and produces the blue screen of death. Fortunately, the error can be fixed by the steps below –

  1. Click on – Start .
  2. Type – cmd .
  3. Press – Ctrl+Shift+Enter .
  4. On the User Account prompt, click Yes .
  5. When Command Prompt is of explicit type – SFC /Scannow.
enter sfc/scannow
  1. Press key – Enter
  2. The tool will start the repair task and show you – Beginning system scan. This process will take some time .
  3. When it reaches 100 percent and completes successfully, restart the computer.
  4. See if the BSOD error still occurs.

Method-6: Use the DISM tool

DISM aka Deployment Image Servicing and Management tool is a default utility for inspecting and repairing .wim files. The Cldflt.sys blue screen error can be triggered by a problem in the Windows image file. So run the tool using these instructions:

  1. Open Command prompt as administrator just like you did in the previous method.
  2. Type – DISM /Online /Cleanup-Image /RestoreHealth.
Use the DISM tool
Use the DISM tool
  1. Type Enter to execute the command line tool.
  2. When the process is finished, reboot the system.

Method-7: Uninstall Windows Updates

Sometimes, Windows updates bring with them bugs that unexpectedly produce different errors. You know Windows 11, like Windows 10, regularly receives quality updates every month. This is developed to protect your system from everyday threats and fix previous errors. A buggy Windows update can cause a Cldflt.sys BSOD error. In this case, the main solution is to remove the update. You can uninstall Windows updates through a variety of methods, such as from Programs and Features, Settings, and Command Prompt. Here we are trying to provide the easiest method –

  1. Click – Search .
  2. Type – Control .
  3. Type – Enter .
  4. When the control panel opens, click – Program and features .
  5. From the left sidebar, select the link – Installed updates .
  6. Find recently installed Windows updates in KB….
  7. Right click on this and select – Uninstall .
  8. You will be presented with a confirmation dialog; Click Uninstall or Yes whichever is showing.
  9. Now hopefully the blue screen with Cldflt.sys will be fixed.

Method-8: Full scan of the built-in Windows Defender

Notorious threats can be the reason for the Cldflt.sys error with BSOD if they get into your system. Threats manipulate registry entries and affect system files to gain full control over the operating system. After that, they start to multiply and infect the computer. So, in case of this Blue Screen error, you need to make sure that there is no virus or malware. If so, the built-in Windows defender is the most powerful tool that not only detects them, but also cleans them. Full scan is preferred as it will take longer but cleans the system more deeply.

  1. Click – Search .
  2. Type – Security .
  3. Press – Enter .
  4. On the Windows security app, click – Virus & threat protection .
  5. From the next page, select – Scan options .
  6. Check – Full scan .
  7. Click on – Scan now .
Full scan of the built-in Windows Defender
Full scan of the built-in Windows Defender


  1. For the scan to complete, note that it will take a long time.
  2. At the end, you will get a notification along with some recommendations. Track them down and clean up the threats.
  3. Restart your PC and then see if the BSOD is fixed.

Method-9: Clean Boot to Fix Cldflt.sys BSOD

Clean boot is a means of starting a Windows PC with a minimal set of drivers. The main convenience in this method is that there are no third-party programs that can cause problems. Loading only the basic drivers can run the operating system, so you should find an opportunity to find out if external software is the culprit. If the computer boots normally, you can assume so. Finally, you can reboot the system in normal mode and uninstall the software. Here are the steps –

  1. press Windows + R .
  2. Type – msconfig .
  3. Type Enter
  4. The system configuration window will appear on the screen, go to the Services tab .
  5. Check the box for – Hide all Microsoft services .
  6. Option – Disable all .
Clean Boot
Clean Boot
  1. Now click on Startup .
  2. Select the link that says – Open Task Manager .
  3. The Task Manager will appear with Startup .
  4. Right click on each application there and select – Disable .
  5. Close the Manager and return to the System Configuration window.
  6. Click Apply and then OK .
  7. Select – Restart on the confirmation prompt.
  8. After the system reboots, check if the Blue screen is not displayed.

Method-10: Perform a system restore

If the above solutions fail to fix the stop error then the next measure is System Restore. This method will help you get your system back to the days when it didn’t crash. Windows 10 or 11 allows you to restore the system to an earlier date and time of your choice. This way you have the freedom to choose the date and time to bring the system back to that state. Here is the method –

  1. Click Start .
  2. Type rstrui .
  3. Type – Enter .
  4. The system recovery wizard will appear; click on – Next .
  5. From the next window, select the date and time when the BSOD error did not occur.
  6. Click – Next .
  7. Now click on – Finish .
  8. A confirmation prompt will appear; choose Yes in this problem.
  9. After finishing the process when your computer boots there will be no blue screen.

Method-11: Reset This PC

When all attempts fail, at last you can Reset PC to fix Cldflt.sys error in Windows 10 or 11. This method includes 2 options – delete everything and keep your files. Deleting everything will change your operating system as if it were installed from scratch. However, keeping your files is more useful as this will help you avoid data loss. Here are the steps –

  1. Press – Winkey+I .
  2. Select – Update & Security .
  3. Click on Recovery from the upcoming Settings page.
  4. On the right pane, under Reset this PC, click Get Started .
  5. On the Choose an option pop-up, select – Keep my files .
  6. Click Next .
  7. Select Reset and confirm if prompted.

Video – How to Fix a Blue Screen of Death on Windows 10 / 11

Ngolongtech hope you find this article helpful and wish you success!!!

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